Update app.py

app.py

@@ -18,8 +18,7 @@ from langchain_community.document_loaders.directory import DirectoryLoader
 from HTML_templates import css, bot_template, user_template
 from langchain_core.output_parsers import StrOutputParser
 from langchain_core.runnables import RunnablePassthrough
-from langchain.retrievers.self_query.base import SelfQueryRetriever
-from langchain.chains.query_constructor.base import AttributeInfo
+from langchain import hub
 
 
 lang_api_key = os.getenv("lang_api_key")
@@ -88,21 +87,9 @@ def create_retriever_from_chroma(vectorstore_path="docs/chroma/", search_type='m
     
     retriever=vectorstore.as_retriever(search_type='mmr', search_kwargs={"k": 7})
 
-    contextualize_q_system_prompt = """If the question is not clear, given a chat history and the latest user question
-    which maybe reference context, formulate a standalone question,
-    which can be understood without the chat history. Do NOT answer the question,
-    just reformulate it if needed and otherwise return it as is."""
-    
-
-    contextualize_q_prompt = ChatPromptTemplate.from_messages(
-    [
-        ("system", contextualize_q_system_prompt),
-        MessagesPlaceholder("chat_history"),
-        ("human", "{input}"),
-    ]
-)
+    rephrase_prompt = hub.pull("langchain-ai/chat-langchain-rephrase")
 
-    ha_retriever = create_history_aware_retriever(llm, retriever, contextualize_q_prompt)
+    ha_retriever = create_history_aware_retriever(llm, retriever, rephrase_prompt)
 
     return ha_retriever